How many bytes takes DateTime format in oracle SQL? - oracle

Umm, Hello, can someone tell me how many bytes takes Date Time format in Oracle SQL pls ?
I tryed to find it with google, but i couldnt find it.
Thank for answer.

You can use DUMP function to retrive information about expression value, like this SELECT DUMP(SYSDATE,10) FROM dual
and it says Typ=13 Len=8: 223,7,4,23,14,17,41,0, so 8 bytes.
From oracle docs
http://docs.oracle.com/cd/B28359_01/server.111/b28286/functions048.htm#SQLRF00635
DUMP returns a VARCHAR2 value containing the datatype code, length in
bytes, and internal representation of expr. The returned result is
always in the database character set.
Aslo, there are two different raw forms for DATEs in Oracle:
https://community.oracle.com/thread/2257401
Type 12 (7 bytes) is used for DATE columns
Type 13 (8 bytes)
is used for other DATE expressions, including DATE literals and results for date arithmetic and functions.

The size of a date time format is fixed at 7 bytes, see Oracle's documentation or alternatively run this:
select vsize(sysdate) from dual
or this:
create table test (dt date);
select data_length from user_tab_columns where table_name = 'ZTEST';

Related

Date Conversion in Oracle (YYYYMMDD format back to YYYYMMDD)

Hi I am pretty much new to Oracle and need an idea on how to do it.
Consideer I have a Text file and the value in the file is
'20180924'
'20180923'
I read these value from the Pro*c and then I add 29 days to it, so the value now changes from 20180924 to 20180953. I don't want that to happen i want the value to be added as
TO_DATE('20180924','yyyymmdd')+29 which returns the value as "23-OCT-18"
The answer is correct but i want the result to also be in the same YYYYMMDD format like 20181023.
How do i achieve this ?
Just format it back.
to_char(TO_DATE('20180924','yyyymmdd')+29, 'yyyymmdd')
Dates do not have a format - they are represented internally by 7 or 8 bytes.
If you want a date to have a format then you will need to convert it to a data type that can be formatted - i.e. a string:
TO_CHAR( TO_DATE( '20180924', 'yyyymmdd' ) + 29, 'YYYYMMDD' )
When SQL/Plus (or SQL Developer) displays date data types they implicitly convert them to strings (since this is more meaningful to you, the user, than displaying the raw bytes) and uses the NLS_DATE_FORMAT session parameter as the format model in this implicit conversion. If you want to change this then you can use:
ALTER SESSION SET NLS_DATE_FORMAT = 'YYYYMMDD';
and then your query:
TO_DATE( '20180924', 'yyyymmdd' ) + 29
should (provided your SQL client uses this setting and does not have their own internal format preferences) give the output you expect. (Note: this will change the default format for the client to display all dates in this session and not just this one statement.)
select TO_NUMBER((TO_CHAR(TO_DATE(HIREDATE,'DD-MON-YY'),'YYYYMMDD')) FROM EMP;
select TO_NUMBER((TO_CHAR(TO_DATE(HIREDATE,'DD-MON-YY'),'YYYYMMDD'))FROM EMP
20201101
select TO_NUMBER((TO_CHAR(TO_DATE(SYSDATE,'DD-MON-YY'),'YYYYMMDD')) FROM DUAL;

Why Does Oracle 10g to_char(date time) Truncate Strings?

I got a bug report where Oracle 10g was truncating return values from to_char(datetime):
SQL> select to_char(systimestamp, '"day:"DD"hello"') from dual;
TO_CHAR(SYSTIMESTAMP,'"DAY:"DD"HE
---------------------------------
day:27hel
Notably, this does not appear to happen in Oracle 11g. My question is, why does it happen at all? Is there some configuration variable to set to tell to_char(datetime) to allocate a bigger buffer for its return value?
I'm not sure but it might be just displaying in SQL*Plus. Have you tried to run it in Toad? Or if you assign result to varchar2 in PL/SQL block and output result?
Here what I've found in SQL*Plus Reference for 10g:
The default width and format of unformatted DATE columns in SQL*Plus
is determined by the database NLS_DATE_FORMAT parameter. Otherwise,
the default format width is A9. See the FORMAT clause of the COLUMN
command for more information on formatting DATE columns.
Your values is trimmed to 9 characters which corresponds to default A9 format. I don't have same version and this behaviour is not reproducing in 11g so can you please check my theory?
I've got the same problem and I know the solution.
I use Release 11.2.0.4.0 but I beleave it is possible to repeat the situation in other versions. It somehow depends on client. (E.g. I cannot repeat it using SQL*Plus, only with PL/SQL Devepoper)
Try this:
select to_char(systimestamp, '"day:"DD"йцукенг OR any other UTF-encoded-something"') from dual
union all
select to_char(systimestamp, '"day:"DD"hello"') from dual;
You'll get the following result:
day:08йцукенг OR any other UTF-encoded-so
day:08hello
You can see the "mething" is lost. This is exactly 7 bytes exceeded because of 7 two-byte simbols "йцукенг". Oracle allocates buffer for the number of characters, not a number of required bytes.
The command
alter session set nls_length_semantics=byte/char
unfortunately does not affect this behavior.
So my solution is to cast a result as varchar2(enough_capacity)
select cast(to_char(systimestamp, '"day:"DD"йцукенг OR any other UTF-encoded-something"') as varchar(1000)) from dual
union all
select to_char(systimestamp, '"day:"DD"hello"') from dual
Explicit typecasting makes expression independent from client or configuration.
BTW, the same thing happens in all implicit to_char-conversions. E.g.
case [numeric_expression]
when 1 then '[unicode_containing_string]'
end
Result might be cutted.

Oracle - Date Format

I need your assistance with converting Oracle dates.
I have a column that stores dates like this 20150731 00:00:34.220. However, I would like to show the column like this 20150731 but when I run a simple select statement to test output I get the following error.
select TO_DATE('20150731 00:00:34.550','YYYYMMDD')
from dual
Error
ORA-01830: date format picture ends before converting entire input string
This query
select TO_DATE('20150731 00:00:34.550','YYYYMMDD')
from dual
leads to error
ORA-01830: date format picture ends before converting entire input string
because you pass string with length 22 characters, but at the same time you pass date format with 8 characters, which obviously doesn't correspond to string. You should write the query as
select to_timestamp('20150731 00:00:34.550','yyyymmdd hh24:mi:ss.ff3')
from dual
As for your table, since you have varchar2 column with dates, you have to take care about table content. Query requires exect matching of the source string and date format.
If you want to show only date without time and you don't need to process this string as date, you can make just
select substr('20150731 00:00:34.550', 1, 8)
from dual
What is the data type of the column? If it is DATE (as it should be) then not it is not stored in the format you say. It is stored in an internal binary format. You would/should use the to_char function to DISPLAY it in whatever format you choose. If you do not use the to_char function, it will be displayed in the format specified by NLS_DATE_FORMAT, which can be specified at several locations.
As for your example, you passed a string format of yyyymmd hh:mi:ss.fff', but you provided a description mask of only YYYYMMDD. It doesn't know what to do with time component. In addition to that when you SELECT TO_DATE, oracle also has to do an implied TO_CHAR to convert it back to a string for display purposes.
In addition, you provided your to_date with a character string that included fractions of seconds. A DATE data type only resolves to seconds. If you need fractional seconds, you need to use TIMESTAMP, not DATE.
If your column is a varchar and you need a date output:
select TO_DATE(substr('20150731 00:00:34.550', 1, 8),'YYYYMMDD') from dual
If it's in a date format and you need a string output:
select to_char(your_column, 'YYYYMMDD') from your_table
Is that being stored in an Oracle datetime column? If not, you may have to do some manipulation to get it into a DD-MON-YYYY format. If it is being stored as a text string you could use SUBSTR( Date_field, Start_Position, Length) to get the first 8 characters. check out this link SUBSTR
Working on the assumption that you're not trying to change the value in the column, and are just trying to show it in the YYYYMMDD format -
As mentioned by a_horse_with_no_name, you'll just need to convert it to a character string. In this example I used systimestamp as my date:
SELECT TO_CHAR(systimestamp,'YYYYMMDD') FROM DUAL
Result:
20160121
That should give you the YYYYMMDD format you want to display.

oracle date format issue

We use Oracle 10.2.0.4.0 database, oracle form builder and report builder for creating forms and reports.
Now the problem is in our production database nls_date_format is dd-mon-rr format. When developer create form in developer suit they give dd-mm-rr format at form level and when data stored in table that date format is dd-mm-rr.
Now when developer run form or report within form builder it gives dd-mm-rr format.but when same form or report run from application server side it gives junk characters in month.date and year print same as date format only month display in junk characters.
Hope you all guide well.
There are two issues.
when data stored in table that date format is dd-mm-rr.
This is completely wrong. Oracle doesn't store the date in the format you see, what you see is for display. Oracle stores DATE in an internal proprietary format in 7 bytes with each byte representing different elements of the DATE.
Byte Description
---- -------------------------------------------------
1 Century value but before storing it add 100 to it
2 Year and 100 is added to it before storing
3 Month
4 Day of the month
5 Hours but add 1 before storing it
6 Minutes but add 1 before storing it
7 Seconds but add 1 before storing it
Do not depend on the locale_specific NLS_DATE_FORMAT. Always use:
TO_CHAR to display the date in your desired format
TO_DATE to explicitly convert the string into date.
Remember, TO_DATE is NLS dependent.
If you only have a date element, and if you do not care about the time element, then better use ANSI Date literal which follows a fixed format 'YYYY-MM-DD'.
only month display in junk characters
This is again because you are depending on the NLS_DATE_LANGUAGE. As I said, you should avoid depending on the locale-specific client settings. Explicitly mention the NLS_DATE_LANGUAGE or use ANSI Date literal if you are not concerned about the time element.
For example,
SQL> SELECT TO_CHAR(SYSDATE, 'DD-MON-RR') dt FROM DUAL;
DT
---------
26-OCT-15
SQL> alter session set nls_date_language='french';
Session altered.
SQL> SELECT TO_CHAR(SYSDATE, 'DD-MON-RR') dt FROM DUAL;
DT
-----------
26-OCT. -15
So, what happened above? for a person using FRENCH nls_date_language, the MONTH is showing junk value. Let's make it NLS independent by explicitly mentioning the nls_date_language.
SQL> SELECT TO_CHAR(SYSDATE, 'DD-MON-RR', 'nls_date_language=english') dt FROM DUAL;
DT
---------
26-OCT-15
Also, the NLS_LANG value might not be correctly set in the OS environmental variable. See Why are junk values/special characters/question marks displayed on my client?

number format in oracle

Hai,
i have a problem with number format.i'm using oracle.
I have a number field in database.But when i retreive it i need to be seen as floating point number
For example:
while retreiveing,now i got the result as 200 DR (DR for Debit,it is given manually).
Now i need to get the result as 200.00 DR as the result.
How can i solve this?Can any one help me?
You can use the TO_CHAR function to explicitely format data:
SQL> SELECT to_char(200.00, 'fm999G999G990D00') FROM dual;
TO_CHAR(200.00,'FM999G999G990D
------------------------------
200.00
Use TO_CHAR like this:
to_char(number,'999999.99')
For example:
SQL> select to_char(1234.5678,'999999.99')||' DR' as display from dual;
DISPLAY
-------------
1234.57 DR
The presence of a debit implies the need for a credit. In Oracle SQL we can use the SIGN() function to tell whether a number is positive or negative...
SQL> select to_char(abs(amt), 'fm999g999d00')||' '
2 ||case when sign(amt) = -1 then 'DR' else 'CR' end as fmt_amt
3 from transactions
4 order by txn_ts, txn_id
5 /
FMT_AMT
--------------
200.00 CR
200.00 DR
788.67 CR
788.67 DR
SQL>
The answers here that suggested TO_CHAR are correct, but if you're calling this SQL from the application code:
Get the number without formatting it with the SQL and then use your programming language to format it. For example, in Java, use the DecimalFormat class. In other words, leave formatting for the application specific code, not for the SQL.
The additional characters can be specified as part of the conversion by enclosing them in double-quotes, which might make things a little more simple:
To_Char(amount,'fm999G999G990D00" DR"')

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